Topic 9: Population, Community, And Ecosystem Ecology Flashcards
1
Q
Ecology
A
The study of the interaction between organisms (biotic) and their living environment (abiotic)
2
Q
Basic Ecology
A
Focuses on undisturbed natural systems
3
Q
Applied Ecology
A
Considers effects of human disturbance
4
Q
Population
A
All individuals of a single species that live together in the same place at the same time
5
Q
Geographical Range
A
Overall space in which every population lives
6
Q
Habitat
A
Environment that offers neccessary biotic and abiotic features for survival
7
Q
Levels of Ecologial Organization
A
Biosphere -> Ecosystem -> Community -> Population -> Organism
8
Q
Science of Ecology
A
- ecologists test hypotheses with observational and experiment data’
- hypotheses an be formed in mathematical models
9
Q
Organismal Ecology
A
Focus on the morphological, physiological, and behavioural adaptions that let an organism to survive in a specific habitiat
10
Q
Population Ecology
A
Study of how populations, groups of organisms of the same species in a given area, change over time and space, and how they interact with their environment
11
Q
7 Population Charactersitics
A
- Geographic Range
- Population Size and Density
- Population Dispersion
- Population Age and Structure
- Generation Time
- Sex Ratio
- Proportion Reproducing
12
Q
- Geographic Range
A
Overall spatial boundaries within which a population lives
13
Q
Habitat
A
Specific environment in which a population lives
14
Q
- Size and Density
A
Relationship between size and density often indicates information about resources used
15
Q
Population Size
A
The number of individuals
16
Q
Population Density
A
The number of individuals per unit area
17
Q
- PopulationDispersion
A
Spatial distribution of individuals within the geographic range
18
Q
Clumped Dispersion
A
Indiviudal are grouped more closely to each other than if they are randomly dispersed
19
Q
Random Dispersion
A
Individuals are randomly distributed
20
Q
Uniform Dispersion
A
Individuals are equally distributed
21
Q
- Age Structure
A
Relative numbers in each age class
22
Q
2 Types of Individual Age Structures
A
- Pre-reproductive
- Post-reproductive
23
Q
Pre-reproductive
A
Ages before reproductive capability
24
Q
Post-reporductive
A
Ages after reproductive capability
25
5. Generation Time
Average time between individuals birth and birth of offspring
26
The _______ the organism, the ________ the generation time
bigger, longer / smaller, shorter
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6. Sex Ratio
Relative proportion of males and females
28
7. Proportion Reproducting
Incidence of reproducing individuals in a population
29
Proportion Reproducing in relevant when…..
Conservation of any species in which individuals are rare or widely dispersed in habitat
30
Demography
Statistical study of processes that change a populations size and density through time
31
Population Growth Factors
Births and Immigration
32
Population Decline Factors
Deaths and Emigration
33
Life Tables
- show number of individuals in each age group
- summarize demographic characteristics of population
34
Demographic Characteristics of Population
- age specific mortality
- age specific survivourship
- age specific fecundity
35
Cohort
Group of individuals of similar age
36
Survivorship Curves
Graph the timing of deaths of individuals in a population
37
Types of Survivorship Curves
- Type I (high survival until old age)
- Type II (constant mortality rate throughout life)
- Type III (high mortality early in life)
38
Passive parental care before offspring are born
behaviors like constructing nests or providing protective environments for eggs, without actively defending them or directly interacting with the developing offspring.
39
Active parental care after offspring are born
behavior that contributes to the offspring's survival, growth, and development.
40
Many young = ?
Little care
41
Few young = ?
More care
42
Semelparity
Individuals are able to reproduce once before death
43
Iteroparity
Individuals are able to reproduce more than once before death
44
Influencers of Life Histories
1. Growth
2. Maturation
3. Reproduction
45
One Reproductive Episode
- devotes all stored energy
- max fecundity
46
Multiple Reproductive Epsiodes
- only some energy devoted
47
Fecundity
the ability to produce an abundance of offspring or new growth
48
Early Reproduction Favoured
- adult survival rate is low
- animals do not grow larger with age
- large size does not increase fecundity
49
Late Reproduction Favoured
- is sexually mature adults likely to become older
- organisms grow larger with age
- larger organisms have height fecundity
50
Exponential Growth Model
Used to understand growth rate when population experience unlimited growth forms a J-shaped curve
51
Exponential Growth Model Formula
r = b - d
52
r = b - d
What does r represent?
Per capita growth rate
53
r = b - d
What does b represent?
Birth rate
54
r = b - d
What does d represent?
Death rate
55
r = 0 when?
Birth rate = Death rate
56
Factors that Limit Exponential Growth
- shortage of resources
- availability of energy from feed
- can affect a population’s per capita growth rate, causing it to slow or stop
57
Logistic Growth Mode
Considers resource limits and results in an S-shaped curve with a carrying capacity
58
Carrying Capacity (K)
- max population size that an environment can sustain
- per capita growth rate (r) decreases as number of individuals in a population (N) approaches K
59
Population Regulation by….
1. Density Dependant Factors
2. Density Independent Factors
60
Density Dependant
Crowding decreases the population
eg. disease
61
Density Independent
Crowding has nothing to do with population decrease
eg. hurricanes
62
Density Dependent Factors
- competition
- predator and prey interactions
- parasites
- infections diseases
63
What are the 2 extremes organisms fall into?
K-selected and r-selected
64
r-selected species
Adapted to rapid changing environments
65
K-selected species
Adapted to slow changing environments
66
Maturation Time K vs r
K: long
r: short
67
Life Span K vs r
K: long
r: short
68
Mortality Rate K vs r
K: usually low
r: usually high
69
Reproductive Episodes K vs r
K: usually several
r: usually one
70
Time of First Reproduction K vs r
K: late
r: early
71
Clutch or Brood Size K vs r
K: usually small
r: usually large
72
Size of Offspring K vs r
K: large
r: small
73
Active Parental Care K vs r
K: often extensive
r: little to none
74
Population Size K vs r
K: relatively stable
r: fluctuating
75
Tolerance of Environmental Change r vs K
K: generally good
r: generally poor
76
Community Ecology
study of how interacting populations of coexisting species within a given habitat shape the structure and dynamics of a biological community
77
Population Interaction
Community is a group of populations of different species living close enough to interact (causing harm or benefit)
78
Symbiosis
Long term association (direct/indirect) of 2 or more different species in a community (effect the fitness of individuals)
79
Symbionts
Individuals involved in symbiosis
80
Predation
(+/-)
Predators gain nutrients and energy, prey is injured or killed
81
Herbivory
(+/-)
Herbivores gain nutrients and energy; plants are killed or injured
82
Competition
(-/-)
Both competing populations lose access to some resources
83
Commensalism
(+/0)
One population benefits; the other population is unaffected
84
Mutualism
(+/+)
Both populations benefit
85
Parasitism
(+/-)
Parasites gain nutrients and energy; hosts are injured or killed
86
Altrusim
(-/+)
Interaction with selfless giving by one organisms to another with no gain for giver (not confirmed in nature)
87
Mimicry
(0/+)
Interaction in which one species (the mimic) benefits from copying another (the model) (not confirmed if it is a symbiotic relationship)
88
Competition
- 2 or more species or populations using the same limited resources
- 2 species using the same resources in the same way can not coexist indefinitely
89
Interspecifc Competition
Different species compete for the same resource in a ecosystem
90
Intraspecific Competion
Members of the same species compete for limited resources
91
Ecological Niche
All the resources uses and the environmental conditions require by organisms
92
Fundamental Niche
Range of convictions and resources that a population could tolerate and use
93
Realized Niche
Range of condition and resources a population can actually use in nature
94
Resource Partitioning
Use of different resources or in different ways to avoid competition
95
Interactive Community
Assemblages of species bound together by complex population interactions
96
Individualistic Community
Population interactions do not always determine species composition, assemblage of species that are individually adapted to similar environmental condition
97
Species Richness
The number of different species in a community
98
Relative Abundance
The proportional representation of a species in a community
99
Trophic
Structure can be visualized as a hierarchy of trophic levels, defined by the feeding relationships among its species
100
Primary Producers
Capture sunlight and convert it to chemical energy
101
Primary Consumers
Herbivores
102
Secondary / Tertiary Consumers
Carnivores or onmivores
103
Detritvores
Scavengers
104
Decomposters
Feed on dead or dying organic matter
105
Trophic Level
Position that an organism occupies in a food chain
106
Ecological Succession
Some what predictable change in species composition over time
107
Primary Succession
Begins on habitats without soil or prior organisms
108
Secondary Succession
Occurs where a community existed in the past
109
Climax Communities
The ultimate ecosystem until something changes
110
3 Succession Hypothesises
1. Facilitation
2. Inhibition
3. Tolerance
111
1. Facilitation Hypothesis
Species modify the local environment in ways that make it less suitable for themselves (makes it better suited for other organisms)
112
2. Inhibition Hypothesis
New species are prevented from occupying a community by species that are already present (succession is not orderly nor predictable)
113
3. Tolerance Hypothesis
Succession happens because competitively superior species replace competitively inferior ones (competition eliminates species that can not harvest scarce resources)
114
Ecosystem Ecology
study of how living organisms (biotic factors) interact with each other and their non-living environment (abiotic factors) within a specific area, forming a system
115
Energy Flows
Energy passes through the ecosystem’s components
116
Chemical Cycles
Nutrients transfer within the ecosystem (cycled between abiotic to biotic)
117
Food Webs in an Ecosystem
1. Grazing Food Web
2. Detrital Food Web
118
Grazing Food Web
Includes the producer, herbivore, and secondary consumer trophic levels
119
Detrital Food Web
Includes detritivores and decomposers
120
Primary Production
- measured for a given area over a given period
- expressed in units of energy or units of mass
121
Cellular Respiration
Metabolic reaction and processes of organisms to breakdown chemical energy from nutrients into a form that can be used to preform work
122
Only ___% of solar energy is converted into chemical energy through photosynthesis
~1%
123
Limiting factors of primary productivity
- availability of sunlight, water, and nutrients
- temperature
- how much photosynthetic tissue is present
124
Biomass
Amount of living organic material in a ecosystem
125
Moving up a biomass pyramid….
Increase in trophic level
126
Moving down a biomass pyramid….
Decrease in biomass and in energy
127
Net Primary Production
(energy captured) — ( amount used by producers for own maintenance)
128
Secondary Productivity
Energy transferred from producer to consumer
129
How is energy spent in secondary productivity?
- stored in new consumer biomass
- used for maintance or locomotion
- lost at heat
130
Ecological Effciency
Percentage of energy is lost when transferred through a food chain
131
Average ecological efficiency
90%
132
What is ecological efficiency determined by?
- harvesting food
- assimilating ingestion food
- new biomass production
133
Energy Flow
Energy limits the length of a food chain (finite)
134
Ecological Efficiency of any trophic
level = ?
(productivity of a level) / (productivity of level below)
135
Pyramids of Energy
Generally have broad bases and narrow tops
136
10% Rule
Only 10% of energy is consumed
137
Pyramids of Biomass
Bio mass at each trophic level is proportional to the amount of chemical energy temporarily stored there
138
Pyramid of Numbers
Shows size of population
(effected by energy and biomass)
139
General Nutrient Cycling Model
Nutrients move rapidly between available compartments, slowly in unavailable compartments
140
Nutrient Cycling in Ecosystem
Earth is a closed system with respect to matter
141
Biogeochemical Cycles
Chemical cycles in an ecosystem that include biotic and abiotic components
142
143
Water is the Staff of Life
Water is the universal intracellular solvent for biochemical reations
144
Carbon is the Back Bone of Life
- provides the backbone of most biological molecules
- stores energy captured by photosynthesis
145
Nitrogen is a Limiting Element
- needed for RNA/DNA
- atmospheric / soil
146
Nitrogen Fixation
Bacteria convert atmospheric nitrogen into ammonium, which is usable by plants
147
Nitrogen Cycle Steps
1. Nitrogen Fixation
2. Ammonification
3. Nitrification
4. Deification
148
Problem with to much Nitrogen
- combustion of fossil fuel reacts with gases are created health hazards
- synthetic nitrogen for fertilizers escapes into atmosphere
149
Phosphorus is a Limited and Essential
Phosphorus lacks a gaseous phase
150
Human impacts of green house gases
- increase the average global temperature; released by landfills, burning fossil fuels, and use of nitrogen fertilizers
151
Biomagnification
- accumulation of harmful chemicals that are retained in the living tissues of consumers in food chains
- top predators have highest concentrations of toxins
152
Why would you expect to see a high species richness in the tropics?
- prolonged evolutionary time
- high energy availability
- stable environmental conditions that favor speciation and reduce extinction rates
153
How would an ecologist investigate the effects of factors that influence populations?
1. Observation and Question:
- The ecologist notices a decline in a species of monkey in a particular rainforest. They ask:
- Why is the monkey population decreasing?
2. Hypothesis Development:
- The ecologist might propose several hypotheses:
- Deforestation is reducing habitat and food sources.
- Increased predation from large cats is causing higher mortality.
- Human activity (like poaching) is reducing numbers.
3. Data Collection:
- Field Surveys: Counting monkey groups in different areas (logged vs. protected forest).
- Camera Traps: Monitoring predator presence.
- GPS Tracking: Following monkey movements to see habitat use.
- Interviews: Talking to local communities about hunting practices.
- Vegetation Sampling: Measuring fruit availability as a food source.
4. Analysis:
- Compare population sizes in disturbed vs. undisturbed areas.
Look at correlations between tree density, food availability, and monkey numbers.
Use statistical tests to evaluate the impact of each factor.
5. Conclusion and Application:
- If the data show that monkey populations are smaller in deforested areas with fewer fruit trees, the ecologist might conclude that habitat loss is the primary factor.
This could lead to conservation actions, like protecting certain areas or restoring fruit trees.
